Wednesday, June 25, 2025

Index - of sorts anyway. Think of it as a guide.

 

Bikes



Clutch


Electrical


Engines and Dyno runs


Exhaust


Maintenance


Suspension



Tuning - Carby

Tuning - Fuel Injection


Moto Guzzi


Cagiva


MV Agusta


Stuff


.

Fuel pump retaining clips in Ducati fuel tanks

 

Turns out, they're called "Terry Clips".  How do I know?  Well.......

A couple of years ago, I sent a rusty 750SS fuel tank out for repair.  It had the rust repaired, and then a liner treatment done.  I've not always been such a fan of the liners.  Done poorly they can lift and cause even more mess, and some of the kits that worked great 25 years ago now just don't.  I try to stay away from them, and certainly won't do it if asked.

digressing.... I did a liner in the mighty KR1S tank back in the day.  It had a small weep from the low point on the LH side - where the water sits when it's on the side stand.  In the instructions, it said to put some nuts and bolts in the tank to act a little more aggressively on the surface rust while you shook it all around like crazy.  Yeah.  Great idea.  You know that little weep you had?  Well, now it's a great big hole you have to weld a plate over.  Awesome.

And then, there was the time someone (let's call him Trev) had to source the chemical that disolves the liner after he'd filled the fuel supply pipe with liner and let it cure.  I think it was MEK?

But I know a bloke who knows a bloke who is very happy to do them, so I take the obvious path to him.

One potential issue though (flagged by another fella who did a few tanks for me, but then decided he'd had enough), is that the treatments used to clean the tanks out may be aggressive on aluminium.  In this case, the rivets that hold the fuel pump mounting clips.  Or don't, when they've been eaten away.

I got this tank back just before Christmas, in the typical end of year rush to get things finished.  I worked over the break, and wanting to get this bike out went to put the tank back together and had a funny feeling something wasn't right.  Couldn't quite put my finger on it though.  When I slipped the pump in, it became pretty obvious.



No clips to hold the pump.  Hmmmmmmmm.  The other shops involved in the repair and liner were closed, so no answers there.  Meaning the question then became "where do I get them?"

And, even more importantly, "what am I trying to find?"  Often, it's the not knowing what to call the thing you're looking for that is the biggest issue.  All these things have names, but often the name is completely irrelevant to what it is or does.  Searched around a bit, and came up with the delightfully random "Terry Clips".  Tel to his mates.  Not sure how I ended up there now, but it's the typical Google this and that and in and out of rabbit holes.  Like this:



20.44.3-1 is the part needed, being 44 - 46mm nominally.  Worked a treat.  But, the next issue was fixing them.  My riveting tools were way to big to get into the tank, and while I considered buying another tool to cut up, I realised there really wasn't enough room anywhere to work it once I'd got it in the tank.  The only alternative I could come up with was screws and nuts, but that presented their own issues.  Screws short enough to not hit the bottom of the tank and damage coating or metal.  And how to hold the nut?

The screws ended up being M3 x 8.  The how being sticky tape, a wee spanner and a clamp to hold the assembly as required, given there's only enough access for one hand.






The typical amount of cussing later, Bob's ya aunty.


And then the pump went back in.

Sunday, April 20, 2025

Hotting up an ST4S - 1026cc, SPS cams, 38mm inlet valves

 I had a bloke ring a few weeks ago and ask about an ST4S ECU upgrade.  I asked him what he was trying to do and he said he had 117hp and would like 130.  I asked what his budget was (gives you an idea of their version of reality), and he replied "a thousand dollars".  I laughed, which wasn't intentional, and probably sounded a bit insulting, but it was an automatic reaction.  It's really not that easy to get a power increase from one of these without spending a lot of money - simply because the bits required cost a lot, as does getting them in.  But sometimes, it's also frustrating, because the expensive bits could just have been fitted at the factory during production.  It's that frustration which, realistically, forms the underlying rant basis of the below rambling. 


Onto the ST4S at hand.  I don't have any before runs to compare to the after run below - I did try to get the bike on the dyno before it came apart, but it's not always easy these days and just didn't come together before I had to pull it apart.  And comparing to all the older runs isn't really practical, as this Dynojet reads lower than the previous ones Dynobike has had.  Realistically, it's probably 12hp or so better at the peak, being nearly 10%.


The thing that has long annoyed me about the ST4 is what it wasn't.  Back then, Ducati had this policy that only the SBK of the day got the best engine, and everything else had to wait for it to trickle down.  So, for 1999 MY, when the SBK was officially named "996" (even though the factory race bikes were first 996cc in 1996 and the 916SPS had been 996cc from 1997), the older 916cc 4V Desmoquattro engine could be used for something else.  Something else being the ST4.  Then, for 2001 MY, when the 996R arrived with the Testastretta 998, the 996cc engine went into the ST.


The problem I have is that the ST4 could have been more, made more annoying that it could've been done with bits off the shelf.  That's what this is here.  Much of the cost involved with this job was related to the age (80k km) and the desire to make it pretty again - painting engines properly is a time and money nightmare.  Any sort of blasting of the cases requires removal of all the bearings, etc, so even if they don't need to be replaced, they're coming out and new ones going in once done.  On this one, every single case and cover was painted.  All those bearings add up. 


The actual hotting up wasn't the big part of the job.  In terms of bits, the 900 crank and SPS cams were on the Ducati shelf in 1999.  As was the 996cc engine.  With the 900 crank fitted - its 68mm stroke is 2mm longer than the 996's 66mm - it has 1026cc, and the marketing department could have played on the concept that stroke = torque and less sporty and the journo's just gobble up shit like that regardless of the truth.  So it's not like they couldn't have claimed it wasn't an SBK engine at all, and a touring special.


The SPS cams?  Well.  The thing is, the SPS cams are most definitely the best Desmoquattro cam they ever made (for a road bike anyway).  For sure, you can find articles like this one - https://www.odd-bike.com/ducati-916-spsps - where they make statements like:


As such the SPS got a reputation as a thundering, maniacal motor that felt way stronger than the dyno numbers would suggest, with a barely-contained fury at lower speeds that made it a bear to ride in slow traffic. Every review reported stalling at idle. Just like any good 916, then. If you meet a 916 owner who claims they are smooth at low speed and easy to ride in traffic, they are either lying or in the process of having a stroke.

which is just complete rubbish.  If you can't make a 916/996SPS idle, you need to stop working on them.  The people responsible for setting up the test bikes certainly needed too. 


We only sold one 1997 916SPS, but we sold quite a few 1998 models and then, for 1999 MY when the 996SPS became a fully complianced road bike in AU, we sold a lot more.  For the 1997 and 1998 models we had to use the Thoroughbred Motorcycles compliance kit originally certified for the 916SP.  But once they came with the normal AU compliance plate, it was happy days.


We were right into playing with cam timing by that time, and we found the same sort of results with the SPS engines as we did with the Biposto engines - advancing the inlet cams gave without taking.  A well set up 996SPS, with the inlet cams advanced 12 degrees and tuned to suit, was, without a doubt, the best engine in the whole range.  Idled like a baby, grandma easy to ride at low speed, went like a rocket (for the time).  Dare I say, it would have made a great sport touring engine.


There's always improvements you can make when reassembling one.  One thing Ducati did then that they appear to have gotten over these days is provide an excessively safe amount of piston to head clearance.  Usually in the 1.4mm range.  That can safely come down to 1.0mm, and these days they're pretty close to that it seems.  On a 98mm bore 996, dropping the squish from 1.4mm to 1.0mm gives a 0.8 point increase in compression ratio just on its own.  Free power right there.  Personally, I aim for 0.95 - 1.00mm on customer bikes, although I'd happily go 0.85 - 0.90mm on my own.  Just make sure it's warm before you spin it to the top.


And if the crank is out, well, why not stick something else in.  The capacity increase with the added 2mm of stroke is only an extra 30cc, which in itself is not really a big deal.  But, that extra 30cc gives an extra 0.3 point increase in comp, so now we're up 1.1 points overall.  Started with 12:1, now we're at 13.14:1.  Daddy loves comp.  Done with std 996 pistons too.  The crank was balanced to suit its new piston and rod mates.  No issues with clearance inside the cases or to the timing shaft (which would have originally been an ST2 part anyway).


The other benefit of the longer stroke is what comes of making it fit.  The first one I did I had some custom 1.2mm base gaskets cut - OEM gasket on a 996 is 0.6mm, plus another 0.6mm to lift the cylinder the required 1mm, minus the 0.4mm of excess squish we wanted to get rid of.  Later, Bruce Meyers told me "I just add another base gasket", which is typically Bruce - simple and effective.  And cheaper - another off the shelf part.  I've done that since.


The advantage here is the head is 0.6mm further away from the crank, and the cams 0.6mm further away from the timing shaft.  So, instead of losing belt tension when you drop the heads to reduce squish with the std crank, you gain belt tension.  Only a little, but it certainly never hurts on these engines.  Some of them can be close to not having enough once the belts have some km on them, even as delivered.


More capacity, more comp, less issues.  


Reshimming everything is always another associated advantage of having them apart.  I typically reduce the crank shimming - I aim for 0.18 - 0.20mm preload with new bearings, and often that seemed to be a reduction of 0.20mm or so from what they came with.


Next it's into the heads.  The 996 and 996SPS cylinder head is the same part.  As are the pistons, meaning that you don't have to worry about machining pistons for piston to valve clearance.  I'm sure Pete Smith had run the inlet cams down to 100 degree centreline on his race engines back in the day with all std bits, so there's plenty there.  But, in this instance, I was fitting some 38mm inlet valves.  So the pistons went off to Special Piston Services to have the reliefs opened a little.  For paranoias sake only, really.


And cams - SPS.  Can be hard to find if you want second handies, as everyone else does too.  Jan at Redfox Grinta was having some made, but I think the grinder may have passed away?  The ones fitted here were Vee Two 604 that I'd had for some time, waiting for a home.  This was as deserving as any.


The std cam timing on the SPS engines was 119/107 centrelines, measured with the belts at the "overtight" 11.5 setting on the Lowener tool.  These days, I've started setting cam timing with the belts at running tension, being 2.5 on the Lowener or 110Hz.  For convenience sake, I'd call 119/107 with tight belts 117/109 with the looser belt setting.  Tom Stalebrandt, who spent a few years working at a Swedish dealer and playing with cam timing as opportunity presented, started retarding exhaust cams and would run the Testastretta Evo engines down to 103 degrees without losing any power, so I followed suit.


On this engine, with belts set to "running tension", I set the cam timing to 104/104 degree centrelines.  To check the timing, I set it up with straight keys in all the cams.  The drop exhaust cam heads fitted to ST and MS4 usually have a 16 degree offset key in the exhaust cams.  From memory the horizontal is advanced and the vertical retarded?  I forget now.  But I checked the timing with straight keys, then pulled the pulleys and headed over to Leigh Farrell's (Cafe Racer) to have him cut some new keyway slots.


For the fuel side, given the ST4S has single injector throttle bodies and I saw no need to complicate matters, I simply replaced the 3 bar fuel pressure regulator with a 3.5 bar part.  The extra 0.5 bar gives an 8% increase in fuel flow, all else being the same.  The change in flow is the square root of the pressure delta, so 3.5 / 3 = 1.167, and square root of that is 1.08.  Or 8%.  From previous testing I know a 996 is potentially fuel flow limited from about 9,500 rpm - see the last graph here https://www.bikeboy.org/duel_inject_throt.html  So I expected that the additional 8% would be fine for this application.


The 3.5 bar pressure regulator used is Bosch part 0280 160 592, and fits in where the Marelli part sits in the fuel pump plate.  Drop in replacement.  So simple, even I made it work.  For a std replacement 3 bar regulator, Bosch 0280 160 560.


I then made up an ECU file based on my ST4S with cam timing, open airbox and mufflers file, with less fuel at the bottom to account for the fuel pressure increase, and a bit more at the top to account for the cams, valves and capacity.  Like that it was pretty good, but once run in went to the dyno for a remap and some numbers.


Which leads me, finally, to the graph.  No before run to compare it to unfortunately, so I'll compare it to the 992cc ST2 job I did around the same time.  Power peaks about 9,350 rpm, which is nice.  Very usable.  And fast.  Standard header pipes, Ducati Performance mufflers, cut airbox lid, maybe a std paper air filter (I'll have to check.), lightened flywheel.  For comparison, the ST2 is externally the same spec.



Owner says in a roll on it happily hangs with his S1000RR mates on the road, which I think came as a surprise to all involved.


The part that annoys me the most is, apart from the 38mm inlet valves, this is off the shelf in 1999 bits.  Nothing special.  Of course, the open mufflers and airbox lid help the peak, but there's no reason they couldn't have delivered a far more serious ST 4V model in 1999 for little effort.


Of course, for the rest of my 1999 MY revisions, the 996 would have SPS cams as well, and the 996SPS would have the 431 inlet cam (1996 996cc factory Corsa) found in the DP catalogue.  The SPS exhaust cam, in terms of area under the curve, is nearing the G cam with much more civilised timing.  It'd do just fine with the 431.


And it would have made the MS4 a whole different animal.  Wheelies into next week.

Thursday, March 20, 2025

Cagiva Raptor TPS baseline procedure - might also work for a TL1000S.

I had a phone call today from a fella asking if I would work on a Cagiva Raptor. Nope was my response - I've just looked and it's 10 years since I've seen a Raptor. Another of the bikes I really never wanted to work on, and am now more than happy to say no to in an effort to simplify my life. But I figured it'd be worth posting this TPS baseline procedure.

The Raptor was somewhat unloved. Great bike, just not wanted. We did a group demo bike ride back in the day with a Raptor, M900ie, 900SSie, 996 and my R1100S I think. The Raptor steered a bit odd - I found getting my weight as far forward as possible helped a lot, as did opening the throttle early. I expect the V-Raptor, with the lower bars and front fairing-ish design, would have been better. It also used a lot less of the front tyre compared to the rear than other bikes. But certainly nice enough for what it was.

Today's bloke was complaining about the "typical" TL1000S 3,000 - 4,000 rpm poor running issue. I suggested he try the TPS baseline we came up with, but he wasn't confident of getting into that sort of thing himself.

Not any sort of official procedure, but we'd been doing TPS baselines for Ducati models for years so it seemed a worthwhile thing to try. I like procedure and repeatability, and this is really the only way to get it. Even if it means they're all bad in the same way, at least then you can start moving forward with some consistancy. The Suzuki ECU in the Raptors didn't have any idle mixture adjustment function, so it was just a matter of manipulating what you had. I believe the Yoshi box could change them, but we never sold enough of the Raptors to make it worthwhile buying one.

From memory (it's a long time since I did any of this, so it's a bit hazy) there was a LCD display on the dash with 3 lines to indicate TPS setting - you'd plug in a diagnostic connector and set the TPS to have the middle line showing with it idling at the desired rpm - I forget what the desired was now. I like things to be more repeatable than that. So, I think we figured out about what the middle line related to in terms of TPS voltage with the throttle blade fully closed on one that ran well, and made it up from there.

Never be afraid to just make shit up, then modify your procedure until it works as hoped.

Procedure was done with the engine not running, back probing the TPS connector with a multimeter to get the voltage reading. We'd generally do it cold, but if it had to be done hot, so be it. The throttle balance set up afterwards was done using the vacuum take offs from the fuel pressure regulator, with all the other vacuum hose guff connected as per normal.

I don't recall if we'd check the idle mixture with the gas analyser now that I think about it. Maybe we did, but as it wasn't anything we could do anything about we didn't bother? Hopefully you'd see 3 to 5% CO - that's where things tend to idle well. But I really don't remember now. Air bleeds were fairly close to full in generally, and winding them out will just lean it out.  We may have been closer to idling too high than too low.

Anyway, good luck, and hope it's of use.
 
 
Raptor / Navigator TPS Setting Procedure

1. Remove airbox, etc, to allow complete access to throttle bodies.

2. Wind idle adjusting knob on LH side off at least two turns.

3. Disconnect throttle linkage at rear butterfly, taking care to remove the plastic washer and spring.

4. Wind rear cylinder throttle stop screw off to allow butterfly to shut completely.  Snap the throttle shut to make sure it can close fully, but have it closed gently with a little push when setting, not jammed.   

(This may have a big rubber cap thingy over it going by photos I have found on line of the throttle bodies.  It's on the other side of the rear throttle body to the TPS)

5. Adjust TPS to give 1.080 volts between brown/black and grey/orange wires – front and centre. The ignition must be turned on to do this.

6. Mark screws with red paint once tightened.

7. Wind idle stop screw back in to give 1.125 volts between the two wires. This is the idle setting.

8. Reconnect throttle linkage.

9. Wind air bleed screws in full closed and set running balance. Connect vacuum gauges to fuel pressure regulator vacuum ports. Leave fuel pressure regulator vacuum lines open. Remove the other vacuum line coming from the rear throttle body next to the fuel pressure reg take off at the check valve on the left hand side and plug. Keep all other vacuum lines/electrical connectors to the airbox, etc connected.

10. Once running balance is set, set idle balance by winding up the idle stop for the front cylinder using the idle adjustment knob. Be sure not to wind idle adjustment knob too far and open throttles off rear cylinder stop screw. This may not result in correct balance, as close as possible is all that is required.

11. Finish idle balance with air bleeds if required. Idle speed should be correct without needing air bleeds to raise speed.

12. Refit all bits.

Monday, May 1, 2023

Ducati DS Cam profile comparison

DS version of the 2V Cam profile comparison -> Click here for link using the same rig as previously modified very slightly to take the M659 head.  And prompting me to buy a new degree wheel.


The DS cams I have to hand are the M659/696/796 8P and the 1100Evo 10B.  George at D Moto sent me a pair of 3V, which are the early 1000 cams.  The later 1000 cams are 7V, and i believe there must also be another version as there are still 3 active # numbers for 1000/1100 cams with the same specs, and one superceded.

The physical difference in the cams from early to late is the large bearing journal on the LH end.  On the later cams it is narrower and further out, and requires a different cam end cap.  As below.  10B on left, 3V on right.


The specs as per the manuals, etc and as measured as below.  I don't have any of the bottom 3 cams to check for now.


I suspect that the 8P and 3V are the same profiles, with the lobe separation opened up (less overlap) for the bigger 1000/1100 engines.  The Evo cam is quite a bit bigger.

Comparing all:


The 8P and 3V.  


And the 3V and 10B, showing how much bigger the Evo's 10B is.

Saturday, April 29, 2023

Multistrada 1000 idling issue - Another (more complete) take on it.

 Some time ago I had a MTS1000 in that had been set up badly to overcome a non idling issue.  That was part of a minor service and not much disassembly, and I got around that electronically.  See here -> MTS 1000 not idling  That particular bike had a very vague history and a couple of dash replacements with no record of actual km.

A bit of MTS1000 info from that report - The MTS1000 was the first Ducati with an idle control valve ("stepper motor", etc).  Any model with an idle control valve doesn't need the air bleeds (the little screws on the sides of the throttle bodies that allow air to bypass the throttle blades) opened, as their primary function is to allow you to set the idle speed.  I also use the air bleeds to equalise the idle mixture between the cylinders, in which case you open the air bleed of the richer cylinder to lean it off to be the same as the leaner cylinder.  Meaning one air bleed should be fully closed.

Seeing air bleeds wound out on bikes with idle control valves really winds me up.  Just not how it's meant to be done.

Recently I had another MTS1000 in for an 80,000km service that I found in the same sort of tune set up - air bleeds wound out one and a half and two and an eighth turns and idle trimmer @ +20.  My response was to wind the air bleeds fully in and set the trimmer to 0 to see what happened, but there was no way it was going to idle successfully.

As I was doing a major service, and had just popped the fuel tank back on to run it, there wasn't a lot of time to be spent pulling it again.  That made it worthwhile to pop off the tank and airbox and have a looksee at the throttle bodies.  As below.




Icky.  But not unexpected for 80,000km, especially on a model where you don't pull the airbox for routine maintenance like you do a Desmoquattro for instance.  None of the 2V models really give you easy access to the throttle bodies to clean them at service.  So I broke out the Threebond Engine Conditioner - which despite the name is a throttle body/intake cleaning spray - and gave it all a good clean up.  I sprayed some down the idle control valve air hose as well, as they can also get claggy.

It's quite awesome for getting fuel residue and combustion gunk off.  I soak carb bits in it, but don't give them too long is my advice.


And Voila!  Lovely.


Back together again, it ended up with both air bleeds still full in and the idle trimmer @ +4, idling happily as desired.



Sunday, April 3, 2022

Undoing an electronic TPS reset on a non linear TPS model - in this instance an ST4S

 .
An issue that comes up with the 59M and 5AM ecu models is the electronic TPS (Throttle Position Sensor) reset capacity the diagnostic tools for these ecu have.  The electronic TPS reset is specifically for linear TPS models.  It has no place for non linear TPS models, but is often performed when it shouldn't be by people who have no idea what they're doing, and can cause issues as it overrules the underlying throttle opening to TPS output relationship to some extent.

How I don't actually know, I don't have the knowledge to understand what the software does when things that shouldn't be done are.

For those who aren't aware of the differing TPS styles and setting procedures, there's some info here:
On to the story - A fellow from interstate emailed me about his poor running ST4S.  The ecu had been reflashed by a Rexxer agent for the previous owner.  He had had it back to the Rexxer agent, who had performed a TPS reset via a diagnostic tool as he had also done when it was originally flashed.  It was no better afterwards.  In my experience the ST4S 59M Rexxer file is pretty good, so there should have been improvement to be had.

I replied that firstly, he needed to undo the electronic TPS reset.  The first time I came across this was a 2002 M900ie that was showing 3 degrees throttle opening on the diagnostic tool @ 700mV TPS output.  I had no idea what to do to fix it, but started guessing at what might help.  Given that flashing the ecu with my CDC tool tends to reset most background settings, I figured I'd try that.  So I read the file from the ecu and then flashed it straight back in again, just to make sure nothing else changed.

After that, the TPS voltage output to ecu diagnostic throttle angle relationship appeared to be about right.  I then carried out the appropriate non linear TPS baseline procedure and the rest of the tune set up and it was then fine.  Well, as good as a std ecu 2002 M900ie can be.

To do this himself, I recommended he download the Guzziddiag IAW5XReader and IAW5xWriter software from here and buy the required cable from Lonelec here for a guaranteed working set up. I also asked that he carry out each step of the process individually, and ride the bike afterwards to see what actually worked and what didn't as such, and provide me with the feedback.

Feedback as follows:

I reflashed the ECU with its original file as you suggested.  Bike ran better immediately. Misfire/stumble gone.

This was the part I was mainly interested in.  A simple before/after only related to the ecu reflashing, and it worked as I'd hoped.  The next part of it was the baseline TPS set up, and the impact of that depends on what has or hasn't been done previously, and how well (or not).

We then followed very closely your video and blog on the TPS reset.  The TPS looked new…no paint to be found at all  and had Allen screw heads.

The initial idle throttle angle was set at 1.6 deg.  With fast idle connection off etc it dropped to 1.3.  Backed out the butterfly throttle adjustment as directed.
We reset the TPS back to zero….played with this setting to ensure we were on zero and not under, as we were relying on the diagnostic tool we only had degrees.  We minutely jiggled the setting up to 0.1 and 0.2 degrees then noticed tightening the screws brought it back down a tad to zero.

So I am guessing its now pretty close.( If we had used voltage it might have been easier).  Reset the idle at 2.6 degrees (USA Bike).  Refit the fairings and took it for a brief ride.

Huge improvement.  Smooth throttle response from low revs.  Engine tone is different, no backfiring or popping on deceleration.  Idle is better, smoother.  
Slow commuter speeds much improved second and third gear 3000 rpm cruising very acceptable.

Again, an improvement as hoped and generally expected when the baseline is done properly.  It really disappoints me that so many of these bikes aren't set up right, and the rubbish reputation they get as a result.

Thinking about it now, as another possibility, you could also try doing another electronic reset to confirm what throttle opening value it resets to.  Then perform the TPS baseline set up procedure, but finish by setting the TPS output voltage to the theoretical corresponding voltage for the required throttle opening.  Ie, 2.4 degrees = 404Mv, 2.6 degrees = 423mV.  Then do another electronic TPS reset.  I wonder if that would also work.  Maybe someone can try it.
.

Sunday, September 20, 2020

Multistrada 1000 not idling - an ecu based solution.

I had an MTS1000 in for some work, part of which was a service after sitting for quite a long time.  One owner bike, but the owner's recollection of what has happened to it service wise over the years was one of the vaguest I've encountered, and the dash had been replaced twice under warranty so total km travelled was even less clear.  With the current odometer reading around 13,000km, I would assume it had had at least once valve clearance service, but I think that's possibly a poor assumption.

Compounding all this was the fact the bill, in dealing with a heap of other stuff, was rapidly closing on a number around the same as the bike's current value.  Which means I'm not too willing to go digging more than I need to.  On one of these, to get to the bits you need to for a valve clearance adjustment, you start removing the panels at the back, move all the way to the front, remove more bits then remove the tank.  Time consuming, and time is money and the money was running for cover.

So an "annual" service is what it got - fluids, timing belts, etc.  I checked the throttle set up, and that's where it went a bit hmmmmm.

The MTS1000 was the first Ducati with an idle control valve ("stepper motor", etc).  Being a 2003 model, it was also the first with the 5AM ecu, in this instance the 103 hardware version.  When they came out, I recall being told that the throttle opening, as displayed by the diagnostic software, was "throttle opening plus idle control valve equivalent".  So when you check the throttle opening angle cold you might see 4.5 degrees, and hot 3.5 degrees or so.  Confusing at best, but when that's what you've got to deal with, that's what you do.

Any model with an idle control valve doesn't need the air bleeds (the little screws on the sides of the throttle bodies that allow air to bypass the throttle blades) opened, as their primary function is to allow you to set the idle speed.  I also use the air bleeds to equalise the idle mixture between the cylinders, in which case you open the air bleed of the richer cylinder to lean it off to be the same as the leaner cylinder.  Meaning one air bleed should be fully closed, although some variation to that will be discussed later.

On this bike, the air bleeds were both open 1 1/2 turns.  The idle trimmer setting of +29 was also a bit concerning, but given the air bleeds were out that far, the trimmer setting didn't really surprise me.

I don't recall it being overly hard to start and get running when I first started it.  Not for a bike that had been sitting for 3 years anyway - the fact it even fired up surprised me.  As it warmed up I got set to check the throttle body set up and wound both air bleeds fully in to adjust the running balance, then got on to the idle mixture.

I found the mixture quite dirty, by which I mean it had a lot of Hydrocarbons and Oxygen in the sample.  This is usually an indication of richness, so knocking the trimmer back was the obvious thing to do.  Dropping it back to 0 both leaned it out (not as much as I might have thought though) and cleaned it up (not as much as I might have hoped though), but the dirtiness remained.  Sometimes, the best way to fix this is to crack the air bleeds a 1/4 turn.  It's amazing how it can drop the HC and O2.  I suspect it may have something to do with the black carbon crap that builds up around the edge of the throttle blade in its closed position, but when it's a couple of hours work to even check that out, you usually don't.

I ended up at 1/2 turn out on one, and 1/4 on the other for around 4.5% CO.  But the idle control valve didn't appear to be doing what I would expect on restart.  I tried doing the test via the diagnostic tool, but it didn't seem to want to do that.  I pulled the hoses off and blew air through the nipples into the manifolds, and they were clear, and with the ignition off the valve was open so I blew back through the valve into the airbox, and that was clear.  But when you turned the key on the valve went to the fully closed position as it's meant to, but then didn't come out again.  I sprayed some carb cleaner into the outlet nipples, then let it sit for a while, then blew that out and tried some Inox to lube it up and then it would, at key on, close then open again.  Fixed!

Not, as it turned out.  By this time the engine was cold.  With the little valve to manifold hoses back on, hitting the start button got a fire and run at very low rpm for 10 seconds maybe, then stall.  I pulled the hoses off, so it had no obstruction, and at that it idled a little longer before it stalled.  I could see the valve doing a little bit of movement during this, whereas previously it'd been doing nothing at all, and I was thinking maybe it's just too lean with the excessive air leak it now has.

Another trick I try with an idle control valve is to disconnect the valve with the ignition on, then with it disconnected turn it off and on again to make sure it has logged a fault, then turn it off, connect it again, turn it back on and clear the fault.  That can sometimes wake them up to some extent, but not here.

On a previous MTS1000 with an issue like this I had played with the base throttle opening (as in what I did to the SC1000 outlined in the Linear TPS setting report, which, I must say, hasn't really worked since) and tried different ecu files and it sort of ended up ok-ish, without being overly convincing.  But, as above, getting that into this one was not an option timewise.

When you have one of these idle control bikes that won't, one of the first things to do is a TPS reset, the electronic procedure via the diagnostic tool.  And, coupled with that, is making sure the idle stops haven't been played with.  There's a fairly obvious stop easily adjusted just behind the throttle cable wheel on the RH side of the throttle bodies, and fairly obvious tempts those that like to fiddle.  Not a good idea on these, but not uncommonly messed with.  The much less obvious stop between the throttle bodies is very rarely messed with, so you usually have a fail safe there.

So, particularly if the paint is missing, you wind that out and make sure it has no influence.  You can see the throttle opening change on the diagnostic tool if it is an issue.  I've seen winding that previously messed with stop out and doing a TPS solve issues like this before.  I must add, at this point, that I've also seen too tight throttle cables have a similar effect, back to the BMW F650GS days.

Anyway, I did a TPS reset to no effect.  I read the file out of the ecu and flashed it back in again (seen that work before).  Didn't help.  Tried a different file with the same result.  I was thinking I might give a 610 ecu and file a go, just to see if anything changed.

But I thought I'd have a look at the original file anyway.  The specified idle speed is no higher than 1300 rpm, but given it was nowhere near that I thought I'd raise it to 1600, just to see if anything changed.  Also, given that the engine would start then peter out and I've seen that due to not enough enrichment, I got into the start up table and richened the soon after start columns to see if that helped.

Below are target idle speed maps (1 row x 16 temp breaks is how you would define this one), which is measured against engine temperature, for two of the MTS1000 files I have, plus what I tried setting it to.


With the original files, the idle rpm I would have expected to see (if all was going to plan) was 1,300 rpm cold and 1,200 rpm hot.  Keep in mind that I didn't put 1,600 rpm in the target rpm table because I actually wanted 1,600.  I put 1,600 in because I wanted to see if it could do it.  There's no point changing it from 1,300 to 1,350, because it's too small a change to really notice definitively.  Make a big change - if it works, great.  If not, move on to the next thing.

The start up table is a pretty cool thing.  Back in the P7 days, there was only an engine temperature correction table to give enrichment for both differing engein temps and cold starting.  Now that might sound like the same thing, but there's differences in fuelling required based in how cold you're starting from and how long it's been running from cold.  I tended to bump this up a bit on some bikes, so that, at say 5 degrees celsius engine temp, it might have in the range of 40% enrichment to make it light up nicely.  I actually think some of the early 851 start issues, where people would claim the bike was "flooding", were due to not enough enrichment to start, but enough to foul plugs and send it all pear shaped.  Sometimes a bike will crank and not fire from cold, but if you let it sit for a minute or two then try again will start straight up, and I think that's because the residual fuel from the first hit, when added to the second hit, is enough and off it goes.  Just a theory.  I've seen lots of late model stuff - M1000, M1100, Guzzi Breva/Sport models like this.

But, with my 851, I find that if it's a hot day - say 30 degrees ambient - it'll fire then not be so happy because it doesn't have enough fuel to keep running due to the trim at 30 degrees not being enough for a "cold start".  Bump that up and it'll start fine, but then on a cold day it's already up and running by the time it hits 30 degrees engine temp and then it's too rich and gets lumpy as it warms up.

The start up table adds fuel based on rotations since started, and is a decaying enrichment table.  Adds quite a lot more fuel for the first 4 or so rotations, then starts dropping it off in the next 4, etc, up to 2,000 or 4,000 rotations, depending on the ecu.  This first appeared with the 1.6M, and it means the engine temp trim table has much less enrichment - usually in the range of 15% maximum.  But add the start up table's 20 - 30% and it'll fire up and go.

This is why the 1.5M ecu runs rich every time you start them for the first 3 minutes or so.  It was annoying there, but better applied here with the 59M/5AM series.

In this instance I made it 10% richer for the columns of 8 to 510 rotations since starting, which would be the first 30 seconds or so of running.  10% is usually enough to pick them up nicely.

But, none of that shit made the slightest difference.  Well, it smelt a lot more fuelly after I turned it off after a couple of 10 - 20 second poor running start attempts.

The next step was to look elsewhere.  One of my pet loves when trying to make things idle is ignition advance.  As in adding more.  These bikes have a separate idle 
ignition advance table, a single line map if you like - 1 row, 32 rpm break columns - and with that you can set the advance when the throttle is closed.  As the lowest rpm break point is usually 900 or 1,000 rpm, it's well under the desired / target idle speed and you can usually taper the amount so at 1,000 rpm it might have 15 degrees, but at the rpm you want it to idle at - and here if it has an idle control valve you need to look at the target idle speed as set in the ecu file - you can drop it back to maybe 10 or so degrees, and then the same again at the rpm break above the target idle speed so the idle is nice and stable and not trying to hunt higher as it picks up engine heat, etc.  Meaning when it's cold and not wanting to idle high, the increased ignition advance at the low idle speed will help keep it running.

On old 851SP - 916SP, which have 290 to 300 degrees cam duration at 1mm lift, you can go up to 25 degrees or so advance at idle and the difference can be quite amazing.  I
gnition advance really is the best stuff.  I have an 851/888SP2/3/4 eprom that has the break points moved around a bit so it has 25 degrees advance at 1,000 rpm and then 15 degrees advance at both 1,250 and 1,500 rpm.  That way it has a heap of advance to support the low idle when cold, and less at the desired 1,250 rpm idle speed and then not changing for 250 rpm so that the idle speed is nicely controllable.

Anyway, I'm meandering - if you have an idle control valve as the MTS1000 does here, and it's doing its job, then you won't have a low idle speed at cold idle.  Well, you shouldn't, and that was the problem with this MTS.

Some of the files have quite surprisingly low ignition advance numbers at idle, in the range of 0 to 2 degrees.  Not as bad an many of the MV models, which have retard, but still enough to lead to some idle instability.  Part of the table from the MTS1000 file is shown below.


Now, some are possibly thinking that going from 0.5 degrees advance to 15 degrees advance is an extreme change.  Correct, it is, but again it's a case of making a change that is noticeable, and really a change that you want.  I usually use a rule of (preferably) at least 10 degrees advance per 1,000 rpm.  That's a bit ish, depending on what you're doing, but it's certainly a lot more valid than 0.5.  At low throttle opening cruise I'll usually add another 5 to 10.  Some of my revised ignition maps for the late models bikes will see an additional 10 to 15 degrees at low throttle over the original.  For an MV, more.

Given the target idle speed is no lower then 1,200 rpm, the advance under that is somewhat irrelevant as long as the idle speed does what it should.  But if it doesn't, or the engine speed drops under load, it should recover.  With 5 degrees less at 1,400 rpm, there's no chance of the idle creeping up, all else being equal.  The advance above that rpm can influence how the engine returns to idle once the clutch is pulled in, and having it low there gets rid of any holding up issues.  Some of the Guzzi Breva/Sport models would do that, and cutting the advance down a lot would fix the issue.  It's not really otherwise important - there's no actual running condition where the engine needs to support load at 1,800 rpm with the throttle closed.  I did have a 1098R like that at one point - it was an issue with them I was told.  I had one go at it, but I think the owner decided I was a dickhead before letting me have a second try (it can be an iterative process), so I didn't get to fix it.

With the increased ignition advance change, the bike idled happily from cold.  As the engine temp rose, the idle speed started creeping up too, getting to over 1,400 rpm before I turned it off.  That made me realise that the issue previously was it wasn't capable of reaching that rpm.  Why I don't know, as it would have been fine when new like that.  Possibly it had a lot of closing clearance, and the high hydrocarbons could back that up.  But it was much happier now, and a win's a win.  With that, I reset the target idle speed and start up tables back to their original setting, meaning the only ongoing change was the ignition advance at idle.  Well, that and the idle trimmer not being +29 any more, which I would hope had made a decent change to how it ran.